Background: Restoration of the gingival margin of Class II cavities with composite resin continues to be problematic, especially where no enamel exists for bonding to the gingival margin. The aim of study is to evaluate the marginal leakage at enamel and cementum margin of class II MOD cavities using amalgam restoration and modern composite restorations Filtek™ P90, Filtek™ Z250 XT (Nano Hybrid Universal Restorative) and SDR bulk fill with different restoratives techniques. Materials and method: Eighty sound maxillary first premolar teeth were collected and divided into two main groups, enamel group and cementum group (40 teeth) for each group. The enamel group was prepared with standardized Class II MOD cavity with gingival margin (1 mm above C.E.J) on both box sides. While the cementum group with the gingival margin (1 mm below C.E.J) on both sides. The enamel and cementum groups were then subdivided into eight subgroups for each (five teeth) with 10 boxes for each group. Subgroups within the main group named according to materials and techniques that were used with it as following: Amalgam subgroup (Permite, SDI), SDR subgroup (DENTSPLY) with bulk technique, Filtek™ P90 subgroup (3M ESPE) with three incremental techniques (Oblique, Horizontal and Centripetal technique), and Filtek™ Z250XT subgroup (3M ESPE) with three incremental techniques (Oblique, Horizontal and Centripetal technique).After specimens were stored in distilled water at 37°C for 7 days. All specimens were subjected to thermocycling at (5° to 55 °C). Microleakage was evaluated by stereomicroscope (20 X). Data were analyzed statistically by Kruskal-Wallis test and Mann-Whitney U-test. Result: All experimental groups showed leakage at cementum more than enamel groups. SDR bulk fill subgroup showed the highest marginal leakage among all experimental groups followed by Filtek™ Z250 XT subgroup with horizontal technique at both enamel and cementum groups. Silorane and Filtek™ Z250 XT subgroups with oblique technique showed the least marginal leakage followed by centripetal technique at both enamel and cementum groups. Amalgam restoration subgroup shows lesser leakage than SDR bulk fills subgroup significantly at both enamel and cementum groups. While it show higher leakage than Silorane subgroup with oblique technique significantly at enamel margin only. Conclusion: The limiting factors for marginal leakage are technique and material dependent.
The present study is to investigate the possibility of using wastes in the form of scrap iron (ZVI) and/ or aluminum ZVAI for the detention and immobilization of the chromium ions in simulated wastewater. Different batch equilibrium parameters such as contact time (0-250) min, sorbent dose (2-8 g ZVI/100 mL and 0.2-1 g ZVAI/100 mL), initial pH (3-6), initial pollutant concentration of 50 mg/L, and speed of agitation (0-250) rpm were investigated. Maximum contaminant removal efficiency corresponding to (96 %) at 250 min contact time, 1g ZVAI/ 6g ZVI sorbent mass ratio, pH 5.5, pollutant concentration of 50 mg/L initially, and 250 rpm agitation speed were obtained.
The best isotherm model for the batch single Cr(III) uptake by ZVI
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Abstract: Background: High percentage of diabetes patients complain from post extraction hemorrhage. Many types of hemostatic materials are used to stop bleeding after teeth extraction: diode lasers are good hemostatic agents owing to their highly absorption by hemoglobin therefore they are used in soft tissue procedures with relatively no effects on dental hard tissues due to their poorly absorption by water and hydroxyapatite. Objectives: The aim of this study is to evaluate the efficiency of diode laser to assist the clot formation after tooth extraction for type II diabetes patients with minimum temperature elevation to prevent periodontal destruction. Materials and methods: From 12 type II diabetes patients (7 males and 5 females wi
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t-Self-Compacting Concrete (SCC) reduces environmental noise and has more workability. This research presents an investigation of the behavior of SCC under mechanical loading (impact loading). Two types of cement have been used to produce SCC mixtures, Ordinary Portland Cement (OPC) and Portland Limestone Cement (PLC), which reduces the emission of carbon dioxide during the manufacturing process. The mixes were reinforced with Carbon Fiber Reinforced Polymer (CFRP) which is usually used to improve the seismic performance of masonry walls, to replace lost steel reinforcements, or to increase column strength and ductility. Workability tests were carried out for fresh SCC. Prepared concrete slabs of 500×500×50mm were tested for lo
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Pharmaceuticals have been widely remaining contaminants in wastewater, and diclofenac is the most common pharmaceutical pollutant. Therefore, the removal of diclofenac from aqueous solutions using activated carbon produced by pyrocarbonic acid and microwaves was investigated in this research. Apricot seed powder and pyrophosphoric acid (45 wt%) were selected as raw material and activator respectively, and microwave irradiation technique was used to prepare the activated carbon. The raw material was impregnated in pyrophosphoric acid at 80◦C with an impregnation ratio of 1: 3 (apricot seeds to phosphoric acid), the impregnation time was 4 h, whereas the power of the microwave was 700 watts with a radiation time of 20 min. A series o
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The current study included the isolation, purification and cultivation of blue-green alga Oscillatoria pseudogeminata G.Schmidle from soil using the BG-11liquid culture medium for 60 days of cultivation. The growth constant (k) and generation time (G) were measured which (K=0.144) and (G=2.09 days).
Microcystins were purified and determined qualitatively and quantitatively from this alga by using the technique of enzyme linked immunosorbent assay (Elisa Kits). The alga showed the ability to produce microcystins in concentration reached 1.47 µg/L for each 50 mg DW. Tomato plants (Lycopersicon esculentum) aged two months were irrigated with three concentrations of purified microcystins 0.5 , 3.0 and 6.0
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Extract from cell culture of medicinal plant like Nigella sativa have been assessed for its cytotoxic properties. Thymol is likely responsible for the theraputic effects of Nigella sativa leaf callus extract. In this short study the inhibitory effect of Nigella sativa leaf callus extract (Thymol) has been studied on Human Lorgnx Epidrmoid Carcinoma (Hep-2) cell line during different exposure period of time (24, 48 and 72 hrs.) using different concentration of the extract (1000, 500, 400, 300, 200 and 100 µg/ml). The optical density of the Hep-2 cells has been readed on 492 nm wave length. Thymol –induced cytotoxicity was (500 µg/ml) which inhibit cell growing compared to the control and this
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The present work determines the particle size based only on the number of tracks detected in a cluster created by a hot particle on the CR-39 solid state nuclear track detector and depending on the exposure time. The mathematical model of the cross section developed here gives the relationship between alpha particle emitting from the (n, α) reaction and the number of tracks created and distribution of tracks created on the surface of the track detector. In an experiment performed during this work, disc of boron compound (boric acid or sodium tetraborate) of different weights were prepared and exposed to thermal neutron from the source. Chemical etching is processes of path formation in the detector, during which a suitable etching solut
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